4
reasons not to buy

A significant number of runners had a hard time getting the right fit and sizing. Vibram advises going one size up in this shoe.

Some runners pointed that a heel loop would have made shoe entry and exit substantially easier.

A few complaints were made about how difficult the shoe was to dry once it got wet.

The water-resistant upper barely shielded the shoe from water, according to a handful of reviewers.

Bottom line

Vibram FiveFingers created a winter version of the massively popular Trek Ascent line in the wool-insulated model. The more aggressive and ultra-sticky outsole makes running on icy and wet conditions a breeze. Provided that runners don’t run on puddles or tackle more than 1 inch of snow, their feet should feel the comforting warmth of the wool collar and sockliner. It delivers a rightful blend of great traction and superior comfort that barefoot runners can hardly find in today’s market.

You're either going to love the look or hate it. We fall in to the latter category. The Trek Ascent Insulated has a lot of character; the sole is incredible, and the choice of materials for the upper and inner will ensure your feet will stay toasty.

Updates to Vibram FiveFingers Trek Ascent Insulated

One of the biggest differences in the FiveFingers Trek Ascent Insulated over its standard model is the use of the Ice Trek rubber compound, which is tailor-made for running in wet, icy conditions.

Because the insulated model is built for the cold months, the shoe is also lined with wool in the collar, the interior, and the sockliner. The wool works as intended as it keeps the foot warm as long as the foot does not get wet in the first place.

To prevent the foot from getting wet, Vibram added a water-repellent upper. Although this is far from being fully waterproof, the water-resistant properties should be able to make runs very comfortable during wintry conditions.

The slight padding in the collar and the tongue makes the shoe more comfortable than the regular model. Plus, it also adds to the warmth in winter.

Vibram FiveFingers Trek Ascent Insulated size and fit

Vibram confirms that the Trek Ascent Insulated runs at least a size smaller than the usual fit in most Vibram shoes. Still, it would be a very good idea if runners can try on the shoe as it would significantly help in getting a more comfortable run. The fit is snug in a good way with plenty of toe box room. As always, the toe slots accommodate all five toes for a natural splay.

Outsole

One of Vibram’s premium outsole technology, the Ice Trek, is used in the underfoot of the Trek Ascent Insulated. The rubber compound is a beast in wintry conditions, particularly on the trails. It has a very aggressive lug design that will raise the confidence of users while running, walking, or hiking. There are also “flex grooves” between the lugs that add flexibility to the shoe. The 4mm outsole provides decent protection and ground feedback at the same time.

Midsole

Handling “midsole” duties is the 4mm PU and wool sockliner. It gives added protection and a little cushioning in the Vibram Trek Ascent Insulated.

Upper

The upper of the Trek Ascent Insulated is one of the most innovative in Vibram’s line. It features a high-tenacity nylon and polyester for a durable, water-resistant, and glove-like fit. As the collar and the interior have wool, the shoe keeps the foot deliciously warm during winter. The fit is snug and really feels like a second skin. A traditional lace-up closure keeps the fit tight and secured throughout the run.